Micro USB Lithium Charger for Cilindrical Lithium Baterry

I got a green laser from ebay, pretty cheap and it included one piece of 18650 Lithium battery, wall charger for the battery, caring box for the laser etc. This raised a question mark given the price and the number of objects I received.

In one day I wanted to charge my 18650 battery and after a while, I heard something popping, a sound from the wall charger. The magic smoke came out and the charger was not good anymore. I assumed that some sort of capacitor was blown given the smell and the smoke :)

I removed the screws and I found a blown capacitor. My initial thought was to scrap the charger. After a good sleep, I came back to better feelings: I can use the plastic housing of the charger to put inside a nice micro USB lithium charger PCBA.

More details about this micro USB charger you can find from Julian's video: New TP4056 Lithium Cell Charger Module with Battery Protection (this is from ebay - I picked one randomly: Micro USB 1A Lithium Battery Charger Module)

This is pretty straight forward project, follow the not-so-detailed steps.

Benefits:

-you re-purposed an object instead of creating more garbage

-this charger can accommodate various lithium size batteries

-you can charge lithium batteries wherever you have a micro USB connection (car, home, outdoors)

Use a screw driver to open the charger (on mine were 5 Philips screws)

Remove the electronic board (PCBA) of the charger, desolder the battery contacts from the electronic board and dispose the electronics board on a recycling bin for electronics

Check where the micro USB charger PCB will sit inside the plastic housing and make a rectangular hole to match the micro USB connector of the PCB.

I used a red hot screw driver tip to drill that hole and a cutter to remove any burrs. You can do the same for the LEDs, it is not mandatory (you can see the LEDs through the plastic case).

Solder the wires to the micro USB charger and to the metal contacts for the battery. Pay attention to the polarity ("+" and "-").

Connect a micro USB cable to check that the charger is working.

Now you have a plastic housing, secure the wires and the micro USB lithium charger inside with hot melt / hot glue.

Make sure that the spring is moving free inside.

Put the charger back, fasten the screws and use your new charger! (the blueish spot on the case is created by the LED from the charger)